Fire-resisting wooden stairs



(No Model.) 2 Sheets-Sheet 1. A. DB MAN. FIRE RESISTING WOODEN STAIRS.

[wwwfbr (No Model.) 2 Sheets-Sheet 2.

A. DE MAN. FIRE RESISTING WOODEN STAIRS.

N0.603,130. Patented Apr. 26, 1898 UNITED STATES PATE T rrion.

ALPHONSE DE MAN, OF DETROIT, MICHIGAN.

FlRE-RESlSTlNG WOODEN STAIRS.

SPECIFICATION forming part of Letters Patent No. 603,130, dated April 26, 1898.

Application filed December 6, 1895. Serial No. 571,234. (No model.)

To all whom it may concern.-

Be it known that I, ALPHONSE DE MAN, of Detroit, lVayne county, Michigan, have invented a new and useful Improvement in Fire- Resisting l/Vooden Stairs and I do declare that the following is a true and accurate description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, and being a part of this specification.

The drawings compose two sheets.

Sheet 1: Figure l is a longitudinal section through a flight of stairs. Fig. 2 is a vertical longitudinal section, on a large scale, showing in detail a portion of the platform and a header or supporting-beam. Fig. 3 is a vertical cross-section, on a large scale, through the inside stringer, showing part of a tread and supporting-cleat, also soffit plastering. Sheet 2: Fig. 4, is a perspective vertical crosssection through a flight of stairs fronting the sofiit with a portion of the plaster and metallic lath removed, showing the construction. Fig. 5 is a horizontal section showing a portion of the first step and riser above it and the stringer and newel in connection with it. Fig. 6 is a perspective view of a portion of the wall-stringer and a corresponding'portion of the carriage-supporting piece in their relative positions, showing on the inside of the wall-s trin ger the supporting-cleats. Between them and the facing are the gains J, which are to receive the end of the treads and risers. 0n the carriage-piece are the vertical blocks, all intended to support the step and riser, also the metallic ribs fastened to the stringer, and the carriage'piece intended to sustain the metallic lath.

My invention relates to the fireproofing of the wooden portion of the inside stairs in buildings.

It consists in insulating the wood by covering it entirely with some fireproof material to exclude the air necessary for combustion, thus preventing live combustion, and if the wood is exposed to an intense and prolonged heat it can only carbonize very slowly. This system of fireproofin g is applied to stairs by insulating independently the main parts composing the stairs namely, the treads, risers, stringers, newels, platforms, also the supporting carriages, beams, and columns.

These parts, for the particular purpose of fireproofing, are made with a core of common wood independently insulated by covering the entire surface of the cores with fireproof sheeting and veneering over the latter at all exposed faces a thin wood veneer to match any required wood finish. The wooden balusters ordinarily used on stairs can be replaced by iron grillwork capped with a light wooden hand-rail. The under side of the stairs and platform can be plastered on metallic lath, which adds to the fire-resisting qualities of the structure.

The following is a detail description of my invention:

I fireproof the wood in stairs by making the treads, risers, and stringers with common wood cores separately insulated by covering their entire surface, including edges and ends, with a fireproof sheeting S, properly lapped. The treads A are then nailed on the edge of the risers B, forming a right angle, and the exposed faces veneered with thin wood veneer A. The stringers D and D when insulated are nailed through their full thickness into the treads and risers, placing the latter in their right position. The cleats 0, previously insulated with a fireproof sheeting, are secured under the treads and back of the risers on the inside of both stringers. The inner side of the stringers above the steps and in front of the risers are then veneered with a thin wood veneer cut out to fit the step and riser. This veneer and the cleats C, under the steps and risers, answer the same purpose as the housing, which is usually done with stringers. The top and face of outside stringer are also veneered with thin veneer to match the other wood finish. A nosing N of the same wood is secured on the corner of the riser and step, making a tight fit between the stringers. Metallic bracket-cleats of appropriate form can be used in place of the wooden cleat C. By such cleats the treads and risers can be secured to the inside of the stringers in such treads and risers can be fastened together by a metallic angle-piece F, Fig. 7, secured underneath the treads and back of the risers in the inner corner formed by these .two parts.

The under side of the stairs can be supported by a carriage-piece K, entirely covered with insulating-sheeting. To the side or on top of the carriage-piece vertical blocks previously insulated can be fastened to support the treads and back up the riser. To the under side of the stringers and carriagepiece metallic ribs, as H, can be fastened horizontally and spaced at a proper distance to receive metallic lath and plaster which is to form the soffit under the stairs. On small stairs, where there is no carriage-piece, the metallic ribs H can be fastened to the under side of the riser parallel with the stringers, which drop below the risers the same height as the rib. The metallic'lath are fastened to the ribs, and the edges are fastened to the bottom of the stringers. The platform P is built solid, the timbers being close together, and is insulated by a fireproof sheeting on top and one below, both closed up tight against the walls and run over at the stair side and lapping one over the other. This side is supported by beam M, independently insulated. Metallic ribs H are fastened to the under side of the beam M and the platform P, spaced at a proper distance to receive metallic lath and plaster, which forms the continuation of the sofiit of the stairs. Thin flooring is put on top of the fireproof sheeting at the upper side of the platform, and a nosing N finishes the edge at the upper riser. The upper edge of the stringer D being veneered at the side, receiving the metallic grillwork which replaces the balusters commonly used and is capped with the wooden hand-rail R, the rail can terminate into a newel E, Fig. 4, which is made of a solid core of common wood entirely covered with a fireproof insulation S, veneered over with thin wood e to match the rest of the stairs. The newel can be secured with metallic angles 0, Figs. at and 5, fastened in the corner at the foot of the post and the stringers.

The newel can be omitted and replaced by grillwork G, Fig. 1. In cases where the beam M has a long span a column may be required to support it. This column can be fireproofed by insulating a stick of timber of proper dimension and securing over all its faces, including ends, fireproof material to exclude air for combustion and covering the exposed sides of the fireproofin g with a suitable facing.

For the fireproof sheeting used to insulate the various constituent members of the structure I employ a porous penetrable material, such as asbestos, as this will permit slow evaporation to take place through its pores, and thus will prevent dry rot in the insulated core. Further, such a material may be readily secured to the core by paste, glue, or other adhesive, which could not be employed for that purpose if a non-porous insulating substance, such as sheet metal,were used. Again, the insulation being penetrable it does not interfere with nailing the parts together.

I desire it understood that the term fibrous is intended to be used as designating the character of material used and that it does not comprehend a metal sheathing, but rather a fibrous material which is sufficiently porous to permit a slow evaporation to take place therethrough.

I claim- 1. In a wood structure, the combination with the various constituent members, of a non-combustible insulating wrapping for the members the wrapping of each member consisting of fibrous penetrable material entirely surrounding, covering and sealing the same, thereby forming a double course of insulating material at the points of union or contact of the various membe's, substantially as described.

2. In wooden fire-resisting stairs, the combination of wooden treads, risers and stringers independently insulated with fireproof material, covering all the faces, edges and ends to exclude air for combustion, with veneer or facings on the exposed parts all well secured together forming the body of a stairs.

3. In connection with wooden fire-resisting stair-bodies composed of treads, risers and stringersinsulated to preventlive combustion and covered on the exposed portions with facing, the metallic bracket-supports secured to the under side of the treads and to the back of the risers in the angle formed by these parts and securing these two parts together substantially and for the purpose set forth.

4:. In connection with wooden fire-resisting stair bodies, the stringers composed of a Wooden core insulated with fireproof-sheeting to exclude air for combustion, having facin gs d d and insulated cleats C, so arranged as to leave a space between the cut-out edge of the facings d d and the cleats 0 these spaces forming the gains J, which are intended to support and form a good connection between the treads and risers and the stringers.

5. In connection with wooden fire-resisting stair-bodies composed of treads, risers and stringers all insulatedto prevent live combustion the wooden carriage-piece K and the vertical supporting blocks both independently insulated with fireproof material to prevent live combustion.

6. The combination of insulated fire-resist in g stair-bodies with the wooden newels, composed of a wooden core independently insulated by fireproof material enveloping it on all sides and ends to prevent access of air for combustion,and the exposed parts being faced with finishing material.

ALPI-IONSE DE MAN.

Witnesses:

F. A. STRATEMEYER, O. M. BRANDT. 

